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NbN superconducting nanowire single photon detector with efficiency over 90% at 1550 nm wavelength operational at compact cryocooler temperature

The rapid development of superconducting nanowire single-photon detectors over the past decade has led to numerous advances in quantum information technology. The record for the best system detection efficiency at an incident photon wavelength of 1550 nm is 93%. This performance was attained from a superconducting nanowire single-photon detector made of amorphous WSi; such detectors are usually operated at sub-Kelvin temperatures. In this study, we first demonstrate superconducting nanowire single-photon detectors made of polycrystalline NbN with system detection efficiency of 90.2% for 1550-nm-wavelength photons at 2.1 K, accessible with a compact cryocooler. The system detection efficiency saturated at 92.1% when the temperature was lowered to 1.8 K. We expect the results lighten the practical and high performance superconducting nanowire single-photon detectors to quantum information and other high-end applications.

Performance of Superconducting Nanowire Single-Photon Detection System

We present our lab cryocooler-based superconducting nanowire single photon detection (SNSPD) system. The dark count rate and system quantum efficiency are investigated at the bath temperature of 3.1 K with a 300-mK temperature fluctuation. The polarization sensitivity of the SNSPD is also measured, and the system counting rate and the timing jitter are discussed.

Recent progress on superconducting nanowire single photon detector

Since the first report on superconducting nanowire single photon detector (SNSPD) in 2001, it has turned to be a‘hotspot’in superconducting electronics. As a novel single photon detector (SPD), SNSPD outperforms the traditional semiconducting SPDs in near infrared wavelength with high detection efficiency, low dark count rate, low timing jitter, high counting rate, wide response waveband and simple circuit etc. In this review we give a brief introduction of materials, fabrication process, properties, system integration and frontier applications of SNSPD from the point of view of application, and also discuss the challenge and future development trend of this field.

Statistical analysis of the temporal single-photon response of superconducting nanowire single photon detection*

A new method to study the transient detection efficiency (DE) and pulse amplitude of superconducting nanowire single photon detectors (SNSPD) during the current recovery process is proposed — statistically analyzing the single photon response under photon illumination with a high repetition rate. The transient DE results match well with the DEs deduced from the static current dependence of DE combined with the waveform of a single-photon detection event. This proves that static measurement results can be used to analyze the transient current recovery process after a detection event. The results are relevant for understanding the current recovery process of SNSPDs after a detection event and for determining the counting rate of SNSPDs.Counting rate is a key parameter of superconducting nanowire single photon detectors (SNSPD) and is determined by the current recovery time of an SNSPD after a detection event. We propose a new method to study the transient detection efficiency (DE) and pulse amplitude during the current recovery process by statistically analyzing the single photon response of an SNSPD under photon illumination with a high repetition rate. The transient DE results match well with the DEs deduced from the static current dependence of DE combined with the waveform of a single-photon detection event. This proves that the static measurement results can be used to analyze the transient current recovery process after a detection event. The results are relevant for understanding the current recovery process of SNSPDs after a detection event and for determining the counting rate of SNSPDs.